Cells

This page will talk about all the projecct exercises we do in class regarding cells. Navigate through the page with the table of contents (right)

Speech: which organelle will be sacrificed?


For the good of the cell, one of us is going to have to be sacrificed so that the rest of us will manage to survive, If you decide to kill me, the cell wall, it will be the GREATEST mistake you have ever made! The cell wall is very important, by killing me you put to risk every one of your lives, I provide rigidity and support for the plant cell, so without me you’d be squishy, imagine a human without the bones, it would not be able to hold itself up, same with the cell, which would not be able to thrive in the wild. I also protect the cell from an excessive intake of water, without me, any extra water will make the cell burst BOOOM like that, I also provide communication with other cells, so if you kill me the plant will not develop properly. I am very important because without me you would die with ease, the cell wall protects the cell from the outside so without me any attacks made to the cell would easily reach the organelles and/or the nucleus terminating the whole cell and everything inside it.

Class Exercises: What cell would I like to be and why?

Introduction of project:

The past few days we have been working on cell division in class, I found out that cells are divided into two groups and then one of them drifts into two smaller categories; prokaryotes, eukaryotes: plants and animals. Working in class really helped solve all doubts that I had because all the names of the organelles eukaryotes have or the names of the parts of the prokaryotes are hard, moreover learning the purpose for the parts was even harder. A few days ago Ms. Silva asked us to do a project, the project was to be done with a partner and then a blog post was supposed to be made about it. The project was about what cell would we choose to be and why.

Project:

In my opinion the best cell to be is an eukaryote, apart from being more complex than the prokaryote because I would have organelles, I would most likely have a defined job and I wouldn’t do everything because there would be more cells around me doing their specific jobs. I guess I am more of a group person so being a single celled, less complex prokaryote doesn’t really call my attention; on the other hand, I have the choice to be a prokaryotic plant cell. I chose to be an animal because animal cells don't seem to have as much protection from the environment as they don't have a cell wall (therefore I am assuming the life of an animal eukaryotic cell is far less dangerous than one of the plant cell) The downside to being an animal cell is that I would not be able to make my own food through photosynthesis, unlike the plant cell, so I would have to rely on the animal's common sense to get food or be a lonely single celled organism (not what I want). Lastly, being an animal cell would have a great digestive system because of lysosomes, little sacks with digestive enzymes; this is good because I hate having stomach aches.


Labeled-Animal-Cell-Diagram.jpg






Project: How EGG-citing!

During class we have been working on a very fun and slightly disgusting project, we had to remove the shell out of two eggs so that they were left with nothing but a thin cell membrane that held it all together yet let some things pass (luckily Ms. Silva did that).

Aim of the project and expectations:


The project aimed to teach us about how the cell membrane works and how osmosis works as well. When I started the project I expected:
  • both eggs to get bigger by gaining mass and increasing its circumference
  • alcohol (one of our liquids) to evaporate

What we did during the lab days:


Once the eggs had no shell, we measured and weighed them and later submerged them in a cup filled of a specific liquid, my group chose to use alcohol and corn syrup. It was a very fun experiment and each day we had to check on the eggs to see if they had grown or if they had gotten smaller and also check on the liquid to see if the amount had increased/decreased. If the amount of liquid had increased and the egg had gotten bigger it meant that the egg was taking in the liquid, if the liquid had a larger volume and the egg got smaller it meant that the egg was releasing its contents.

Observations during the experiment:

During the experiment my team and I noticed that:
  • The eggs never appeared bigger
  • Syrup egg got squishier
  • Alcohol egg became harder as days passed -
  • Alcohol egg got whiter
  • Syrup egg became orange
  • Liquid was reduced, especially in the Alcohol egg
  • Syrup in the cup became clearer
  • Once opened, the syrup egg was liquid while the alcohol egg had been solidified

Tables and Graphs:

Each day we recorded our data and other groups' data (Vitor Takasus and Bruno Choe's group) so we could make an average, we collected data from 2 groups not counting ours and we each made them into table:
ta.PNG

Later each one of us made graphs to be able to compare easier:
graph_alcohol.PNG
2_GRAPH_OF_EPICNESS.PNG

*Data shown is an average of all collected data
Note: In the graph regarding the syrup egg, mass and liquid overlap each other in day 3

Conclusion:


The alcohol egg both released its liquids and also brought in the alcohol as the egg was the same size and the same circumference yet alcohol was inside the egg. The alcohol egg, via osmosis and diffusion, was filled with alcohol molecules which hardened the egg due to alcohols effect, denaturation[1] .
To explain what denaturation was I did some research and found out that "Denaturation is the alteration of a protein shape through some form of external stress (for example, by applying heat, acid or alkali)"[2] What this means in the experiment can be seen in a video presentation in the website called http://highered.mcgraw-hill.com . This website tells us that denaturation causes the proteins to become solid, therefore the alcohol (which is a base) through the process of denaturation caused the egg to become solid.
Based on the results I can infer that osmosis happened as the eggs concentration of water inside was higher than the water outside in the cup therefore its circumference and mass got smaller from day 1 to day 2. You can appreciate a slight increase of mass in the 3rd day but I assume that data must have been measured incorrectly as it does not match the other group.
The solidification of the egg is proof that alcohol did enter it through diffusion.

The syrup egg lost circumference over time yet only lost mass during the 1st to 2nd days and on the third gained, I compared all the data not only from my group but from another 2 groups and they all have the same results, the egg losing mass in the first day but gaining some back. The circumference of the egg was a strange case as some groups lost circumference and then gained more while others lost circumference all the time. I can infer due to the eggs orange color after the 3 days and due to the syrup becoming more fluid and a lot clearer that the egg lost water through osmosis because its concentration was higher. The egg also went through the process of diffusion as it turned orange, with that observation we can tell that something that was not water entered the egg.


Evaluation of the experiment:



I think this experiment really helped me understand:
  • Osmosis and diffusion better because after the data by both the eggs I can see that osmosis and diffusion happen predominantly one way yet they still happen the other way in a smaller manner.
  • How bad eggs can smell after days in the same liquid and
  • A new quality or process regarding proteins, which is denaturation. Denaturation can be caused by heat, or an acid or base and that it kills bacteria and solidifies the proteins.

Error analysis:

In this experiment, lots of thing could have/went wrong;
We could have measured incorrectly because of the precision of the tools we used
The scale we used to weigh the eggs could have not been properly calibrated
I spilled some liquid while performing the daily routine of taking out the egg and measuring everything.

Improvement Suggestions:

To improve this experiment we could;
  • Use more precise tools
  • Be more careful with liquids
  • Get a teacher or someone with experience to calibrate the scale

Importance of osmosis/diffusion in living things:

With this experiment I have learnt of the importance of these two processes in living things. For example without osmosis the human body would not sweat properly and would become overheated, also without diffusion the lungs and alveoli would not be able to do their job properly as oxygen molecules and carbon dioxide molecules along with other gasses need to pass from capillaries to alveoli and vice versa.

Team Evaluation:

I kind of liked my group, I think we could have done a better job at not getting distracted or not leaving all the work to just 1 or 2 people, moreover I learned a lot of new things with the group and even when we were getting side tracked, when one of the team members needed help he received it from his/her peers.


Here are some pictures of our egg-celent adventures: (yes, I just did that)

IMAG0053.jpg
The eggs after the egg-speriment; left alcohol, right syrup


IMAG0056.jpg
The eggs, once they were open, left syrup, right alcohol


sources:
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/L/Lysosomes.html
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/L/Lysosomes.html
http://www.sciencecontrol.com/labeled-animal-cell-diagram.html

Cell project: Cell Summative Assesment:

To finish up with this chapter we had to make a project of our liking which the company ZOINKS! could use as material for teachers.
I chose to do a video which would be a talk show. To find out more about why I chose it and how I did it you can go to the section; "I talk about the project!"
http://www.youtube.com/watch?v=xTf-GLDbCGo -link to youtube video
NOTE: PLEASE WATCH IN YOUTUBE AND NOT IN WIKISPACES
  1. ^ http://www.elmhurst.edu/~chm/vchembook/568denaturation.html
  2. ^ http://www.sciencedaily.com/articles/d/denaturation_(biochemistry).htm